Salient features of a parallel programmable interface-8255, Computer Engineering

Assignment Help:

Determine the salient features of a parallel programmable interface, 8255.

  • 24 I/O lines in 3 8-bit port groups - A, B, C
  • A, B can be 8-bit input or output ports
  • C can serve as 2 4-bit input or output ports
  • 3 modes of operation:

- Mode 0: A, B, C simple input or output level sensitive ports

- Mode 1: A, B input or output ports with strobe control in C

- Mode 2: A is bidirectional with control/handshake in B and C

  • A, B can only change 1 byte at a time
  • C has individual bit set/reset capability
  • Advantage is non-dedicated circuit can change port configuration with software and no 'glue logic'
  • Ports A, B, and C are used for I/O data.
  • The control register is programmed to select the operation mode of the three ports A, B, and C.
  • Mode0: simple I/O mode
  • Any of the ports A, B, CL and CU can be programmed as input or output.
  • No control of individual bits (all bits are out or all bits are in)
  • Mode 1: Ports A and B can be used as input or output ports with handshaking.
  • Mode2: Port A can be used as bidirectional I/O port with handshaking

 


Related Discussions:- Salient features of a parallel programmable interface-8255

Staircase, What is the aim of a stair case light is controlled by two switc...

What is the aim of a stair case light is controlled by two switches one at the top of the stairs and another at the bottom of the stair

Find the width of a time division space switch, I n a time division space s...

I n a time division space switch the size of the control memory is N and its Width:  (A) Log 10 M  (B) Log e M  (C) Log N M  (D) Log 2 M Where N are the ou

What is ai checkers, The major programs here are Arthur Samuel's, the rote ...

The major programs here are Arthur Samuel's, the rote learning method which is a lot like a memory based method, generalization learning which is a lot like backprop and a signatur

Explain active matrix or thin film transistor technology, Q. Explain Active...

Q. Explain Active Matrix or Thin Film Transistor technology? This is known as TFT (Thin Film Transistor) technology. In this there is a transistor at every pixel acting as a r

Matlab, 33.A juice company manufactures one-gallon bottles of three types o...

33.A juice company manufactures one-gallon bottles of three types of juice blends using orange, pineapple, and mango juice. The blends have the following compositions: 1 gallon or

Assessing heuristic searches-artificial intelligence, Assessing Heuristic S...

Assessing Heuristic Searches Given a specific problem you want to create an agent to solve, there can be more than one way of specifying it as a search problem, more than one o

Determine a sample rate required for telephone conversation, A sample rate ...

A sample rate of            is required for a good quality representation of telephone conversation. A sample rate of 50 times/second /mile of distance travelled are needed fo

Write the benefits of broadcast model approach, a. Determine the non-functi...

a. Determine the non-functional system requirements that might be chosen for an application for a particular style and structures? b. Write the benefits of broadcast model appro

What is the type of process identifiers, What is the type of Process Identi...

What is the type of Process Identifiers? Identification of the real user Identification of the effective user Identification of the real group Identification

Explain the various interface circuits, Explain the various interface circu...

Explain the various interface circuits.  An I/O interface having of circuitry required to connect an I/O device to computer bus. One side having of a data path with its associa

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd